Chapter 7 - The Axial Skeleton Flashcards
Axial Skeleton
80 bones on longitudinal axis
Appendicular Skeleton
126 bones of upper and lower limbs and girdles.
Long bone
Shaft and variable number of extremities or epiphyses, slightly curbed for strength. Mostly compact bonne tissue, but some spongy in ends. Femur, tibia, fibula, humerus, ulna, radius, phalanges.
Short bone
Somewhat cube shaped, spongy except compact surface. Wrist, ankle.
Flat bone
Thin, plate of compact over plate of spongy, cranial bones, sternum, ribs, scapulae.
Irregular bone
Vary, vertebrae, hips, some face, calcaneus.
Sesamoid bone
tendons with friction (palms and soles), pattellae, quadriceps femoris tendon. Protect tendons.
Sutural bone
Small bones located in sutures between some cranial bones.
Frontal bone
Forehead
Supraorbital margin, foramina, notch, frontal sinuses
Superior border of the orbits, the frontal bone thickens.
Foramina = hole (brow pressure point)
incomplete hole = notch
Parietal bones
Sides and roof of cranial cavity.
Temporal bones
Inferior lateral aspect of the cranium and part of the cranial floor.
Temporal squama = temple
Zygomatic, mastoid, styloid processes
Z=cheek, M=attachment point for neck muscle
S=attachment for ligaments of tongue and neck
Madibular fosa
Socket on the inferior posterior surface of the zygomatic process of each temporal bone
Zygomatic arch
zygomatic process of the temporal bone and the temporal process of the zygomatic bone.
External auditory meatus
Ear canal, detects sound waves
Internal auditory meatus
opening through facial 7 nerve and vestibulocochlear 8 nerve
Occipital bone
Posterior part and most of the base of cranium
Foramen magnum
Inferior large hole, medulla oblongata connects with spinal cord through this hole
Occipital condyles
articulate with depressions on c1 for”yes” oval processes with convex surface on either side of the foramen magnum.
External occipital protuberance
Prominent midline projection on the posterior surface of the bone (bump above neck)
Sphenoid bone
keystone of cranial floor, butterfly.
Sella turcica
Bony saddle-shaped structure on the superior surface of the body of the sphenoid.
Optic foramen
Through which the optic 2 nerve and ophthalmic artery pass into orbit
Ethmoid bone
spongelike appearance. (1) part of the anterior portion of the cranial floor; (2) the medial wall of the orbits; (3) the superior portion of the nasal septum, a partition that divides the nasal cavity into right and left sides; and (4) most of the superior sidewalls of the nasal cavity. The ethmoid bone is a major superior supporting structure of the nasal cavity and forms an extensive surface area in the nasal cavity.
Superior and middle nasal conchae
scroll-shaped projections lateral to the nasal septum. The conchae greatly increase the vascular and mucous membrane surface area in the nasal cavity, which warms and moistens (humidifies) inhaled air before it passes into the lungs. The conchae also cause inhaled air to swirl; as a result, many inhaled particles become trapped in the mucus that lines the nasal cavity. Increase surface area for smell.
Nasal bones
Small, flat, rectangular bones that form the bridge of the nose.
Lacrimal bones
(look like a fingernail) Posterior and lateral to nasal bones, form medial wall.
Lacrimal fossa
a vertical tunnel formed with the maxilla, that houses the lacrimal sac, a structure that gathers tears and passes them into the nasal cavity
Palatine bones
L-Shaped, posterior portion of the hard palate, part of the floor and lateral wall of the nasal cavity, small portions of the floors of the orbits.
Inferior nasal conchae or turbinates
Scroll-like bones form part of the inferior lateral wall of the nasal conchae, increase SA of air but dont smell.
Vomer
Triangular bone on the floor of nasal cavity. Forms inferior portion of the bony nasal septum, the partition that divides the nasal cavity
Maxillae & Hard Palate
Upper jawbone.
Hard Palate is the roof of mouth.
Maxillary sinus
Empties into nasal cavity
Infraorbital foramen
Opening in the maxilla inferior to the orbit, allows passage of the infraorbital blood vessels and nerve
Zygomatic bones
Cheekbones.
Mandible
Lower jawbone. strongest and only movable in skull.
Mandible - Body
Curved horizontal portion
Mandible - Rami
Two perpendicular portions
Mandible -Angle
where each ramus meets body
Mandible - Condylar processes
Posterior process that articulates to form TMJ
Coronoid processes
attaches temporalis muscle
Temporomadibular joints
TMJ
Mandible - Alveolar process
Ridge-like arch containing the alveoli (sockets for lower teeth)
Nasal septum
made up of vomer, septal cartilage and perpendicular plate of the ethmoid bone.
Orbits or orbital cavities
Seven bones join to form eye sockets.
Coronal suture
Unites frontal bone and parietal bones
Sagittal suture
Unites parietal bones on the superior midline of the skull.
Lambdoid suture
Unites the parietal bones to the occipital bone.
Squamous sutures
flat, unite parietal and temporal bones on the lateral aspects of the skull.
Paranasal sinuses
Cavities within certain cranial and facial bones near the nasal cavity. Lined with mucus membranes
Fontanels
Soft spots, areas where unossified mesenchyme develops into dense connective tissue. provide space for growth of bones.
Hyoid bone
Does not articulate. Anterior neck between mandible and larynx, supports tongue. consists of horizontal body and paired projections called the lesser horns and the greater horns
Normal curves
Four curves, increase its strength, help maintain balance in the upright position, absorb shocks during walking, and help protect the vertebrae from fracture.
Cervical and lumbar
7 and 5
Thoracic and sacral
12 and 1
Intervertebral disc
Found between the bodies of adjacent vertebrae from c2 to sacrum. The discs form strong joints, permit various movements of the vertebral column, and absorb vertical shock. Under compression, they flatten and broaden.
Nucleus pulposus
inner soft, pulpy, highly elastic substance called the nucleus pulposus in discs
Vertebral body
thick, disc-shaped anterior portion, is the weight-bearing part of a vertebra, contain nutrient foramina
Vertebral arch
Two short, thick processes project posteriorly from the vertebral body and then unite with the flat laminae
Vertebral foramen
vertebral body and the vertebral arch sur- round the spinal cord
Vertebral canal
the vertebral foramina of all vertebrae form the vertebral (spinal) canal.
Intervertebral foramen
When the vertebral notches are stacked on top of one another, they form an opening between adjoining vertebrae on both sides of the column. Each opening, called an intervertebral foramen, permits the passage of a single spinal nerve carrying information to and from the spinal cord.
Transverse processes
At the point where a lamina and pedicle join, a transverse process extends laterally on each side.
Spinous process
At the point where a lamina and pedicle join, a transverse process extends laterally on each side, attachment point for muscles
Cervical vertebrae c1-c7
Smaller bodies, larger arches. Three foramina, bifid-branch into two small projections.
atlas c1
first cervical vertebrae inferior to the skill, lacks body, yes
axis c2
Does have body,
dens or odontoid process
peglike process projects superiorly through the anterior portion of the vertebral foramen, makes a pivot on which the atlas and head rotate. no
thoracic vertebrae t1-t12
larger and stronger, articulate with tubercles of ribs
vertebrocostal joint
articulations between the thoracic vertebrae and ribs. movements of the thoracic region are limited by the attachment of the ribs to the sternum.
lumbar vertebrae l1-l5
Largest, strongest, unfused. Short and thick projections.
Sacrum
triangular bone formed by five sacral vertebrae, completed age 30.
Anterior sacral foramina
At the end of four transverse lines that mark the joining of the sacral vertebral bodies.
Median sacral crest
Convex, posterior surface of the sacrum, fused spinous processes of the upper sacral vertebral
Posterior sacral foramina
Four pairs which connect with anterior sacral foramina to allow passage of nerves and blood vessels.
Sacral canal
Continuation of the vertebral cavity
Sacral promontory
Anteriorly projecting border of the base, is used for measurements of the pelvis
Sacroiliac joint
large ear-shaped auricular surface that articulates with the ilium of each hip bone to form the sacroiliac joint
Lumbosacral joint
and the base of the sacrum articulates with the body of the fifth lumbar vertebra to form the lumbosacral joint
Coccyx
Triangular, formed by fusion of ~4 coccygeal vertebrae.
Sternum or breastbone
Flat, narrow, center of the anterior thoracic wall.
Manubrium
Superior, handle like
Body
Middle, largest
xiphoid process
Inferior, smallest, sword shaped
Sternal angle
Junction of the manubrium and body
Suprasternal notch
Manubrium has a depression on its superior surface
Clavicular notches
Articulate with the medial ends of the clavicles to form sternoclavicular joints
Costal cartilage
direct anterior attachment to the sternum by a strip of hyaline cartilage called costal cartilage
contribute to the elasticity of the thoracic cage and prevent various blows to the chest from fracturing the sternum and/or ribs
True ribs 1-7
costal cartilages and attach directly to the sternum
false ribs 8-12
Costal cartilages either attach indirectly to the sternum or do not attach to the ster- num at all. The cartilages of the eighth, ninth, and tenth pairs of ribs attach to one another and then to the cartilages of the seventh pair of ribs. These false ribs are called vertebrochondral ribs
floating ribs 11-12
costal cartilages at their anterior ends do not attach to the sternum at all. These ribs attach only posteriorly to the thoracic vertebrae.
Rib - Head
a projection at the posterior end of the rib
Rib- articular facets
pair of articular facets (superior and inferior). The facet of the head may fit either into a facet on the body of a single vertebra or into the demifacets of two adjoining vertebrae to form a vertebrocostal joint
Rib-Tubercle
The neck is a constricted portion of a rib just lateral to the head. A knoblike structure on the posterior surface, where the neck joins the body, is called a tubercle
Rib-Body
Main part.
Rib-Costal angle
A short distance beyond the tubercle, an abrupt change in the curvature of the shaft occurs.
Rib-Costal groove
The inner surface of the rib has a costal groove that protects the intercostal blood vessels and a small nerve.
Herniated disc or slipped disc
If the anterior and posterior ligaments of the discs become injured or weakened, the pressure developed in the nucleus pulposus may be great enough to rupture the surrounding fibrocartilage (annulus fibrosus). If this occurs, the nucleus pulposus may herniate (protrude) posteriorly or into one of the adjacent vertebral bodies
Abnormal curves of the vertebral column
Various conditions may exaggerate the normal curves of the vertebral column, or the column may acquire a lateral bend,
Spina bifida
congenital defect of the vertebral column in which laminae of L5 and/or S1 fail to develop normally and unite at the midline.
